Nonaqueous electrolyte secondary batteries, particularly lithium secondary batteries, have a high energy density and are therefore in wide use as batteries for personal computers, mobile phones, mobile information terminals, and the like. Such nonaqueous electrolyte secondary batteries have recently been developed as on-vehicle batteries.
For example, Patent Literature 1 discloses a nonaqueous electrolyte secondary battery containing (i) a polyolefin porous film and (ii) a porous layer containing a polyvinylidene fluoride-based resin.